Tools and technology for high-fidelity mesoscale diffusion MRI

PROJECT ABSTRACT The NCBIB P41 Center for Mesoscale Mapping (CMM) is dedicated to driving the convergence of tools and technologies for imaging and probing human brain structure and function at the mesoscopic scale. Technology Research and Development (TRD) Project 3 focuses on developing high-fidelity mesoscale diffusion MRI tools and technologies for investigating human brain microstructure and connectional anatomy at unprecedented resolutions, taking advantage of advances in MRI hardware over the past two decades. The greater availability of high-performance gradients and ultra-high field strengths for MRI is increasingly allowing for imaging of tissue microstructure at the mesoscopic scale, yet such hardware advances also pose significant challenges to obtaining high image quality throughout the whole brain. TRD3 seeks to overcome these limitations by developing high-fidelity, high-spatial resolution acquisition technology and interpretive frameworks, unlocking the full potential of high-performance MRI systems for acquiring biological insights at the mesoscopic scale. By integrating advanced diffusion-relaxometry methods, we aim to generate parametric maps of cellular-scale biophysical properties, providing insights into brain structure and organization across multiple scales. TRD3 will tackle technical challenges related to imaging at ultra-high field strengths, including motion artifacts, eddy current distortions, and field inhomogeneities. Our work will focus on three key objectives: (1) Developing robust sub- millimeter acquisition techniques for artifact-free diffusion MRI, (2) Innovating on parallel transmit (pTx) strategies to achieve uniform spin-echo diffusion MRI at 7T, and (3) Creating tools to link mesoscale diffusion MRI data with the underlying tissue microstructure. These technologies will offer powerful new tools for fundamental neuroscience research, with applications to understanding brain organization and the biological basis of neurological and psychiatric disorders.